Verify Android User input date

How do I verify that the date entered by the user is valid or invalid?

Privatepattern pattern;PrivateMatcher Matcher;Private StaticFinal String Date_pattern ="(0?[ 1-9]|1[012]) [/.-] (0?[ 1-9]| [12] [0-9]|3[01]) [/.-] ((19|20) \\d\\d)";/** * Validate date format with regular expression* @param date date address for validation* @return true valid date for MAT, false Invalid date format*/ PublicBoolean Validate (final String date) {Matcher=pattern.matcher (date); if(Matcher.matches ()) {matcher.reset (); if(Matcher.find ()) {String day= Matcher.group (1); String Month= Matcher.group (2); intYear = Integer.parseint (Matcher.group (3)); if(Day.equals (" to") &&(Month.equals ("4") || month. Equals ("6") || Month.equals ("9") ||Month.equals (" One") || Month.equals ("Geneva") || month. Equals (" .") ||Month.equals (" the"))) {             return false;//Only 1,3,5,7,8,10,12 have          }                   }      Else{           return false; }          }  Else{      return false; }              }

Privatepattern pattern;PrivateMatcher Matcher;Private StaticFinal String Date_pattern ="(0?[ 1-9]|1[012]) [/.-] (0?[ 1-9]| [12] [0-9]|3[01]) [/.-] ((19|20) \\d\\d)"; /** * Validate date format with regular expression * @param the date date address for validation * @return true Valid Date format, false invalid date format*/ PublicBoolean Validate (final String date) {Matcher=pattern.matcher (date); if(Matcher.matches ()) {matcher.reset (); if(Matcher.find ()) {String day= Matcher.group (1); String Month= Matcher.group (2); intYear = Integer.parseint (Matcher.group (3)); if(Day.equals (" to") &&(Month.equals ("4") || month. Equals ("6") || Month.equals ("9") ||Month.equals (" One") || Month.equals ("Geneva") || month. Equals (" .") ||Month.equals (" the"))) {             return false;//Only 1,3,5,7,8,10,12 have          }           Else if(Month.equals ("2") || Month.equals (" Geneva")) {               //Leap Year               if(Year%4==0){                   if(Day.equals (" -") || Day.equals (" to")){                       return false; }                   Else{                       return true; }              }              Else{                  if(Day.equals (" in")|| Day.equals (" -")|| Day.equals (" to")){                      return false; }                  Else{                      return true; }              }          }          Else{                             return true; }      }      Else{           return false; }          }  Else{      return false; }              }

Then put the following code in the onclick ():

Matcher = pattern.compile (date_pattern). Matcher (Birthday); // Birthday Validator    Else if (! matcher.matches ()) {    "Invalid birthday! " , Toast.length_short). Show ();                    }

Verify Android User input date